When starting up a fuel cell in a low temperature environment such as a subzero environment, there are performed a temperature rising control for raising the temperature of the fuel cell by using heat etc. generated through the power generation of the fuel cell and a low-temperature startup operation that includes a recovery operation for removing moisture inside the fuel cell (particularly, in the cathode). This recovery operation is performed in order to restrain the output performance of the fuel cell from being decreased due to a so-called flooding state.
As the recovery operation in such the low-temperature startup operation, JP4575693B2 proposes a fuel cell system that supplies dry air to a cathode at the time of the low-temperature startup of a fuel cell (hereinafter, also described as “dry air supply process”) to vaporize moisture in the cathode and discharges the moisture into a cathode discharge flow channel.